Addressing AI's Power Consumption Challenges Fujitsu's Three Energy-Saving Technologies

Unlike virtualization technology, which shares GPU memory among multiple programs, ACB detaches the GPU along with its memory and reallocates it to other AI programs, effectively eliminating memory constraints. This technology is particularly beneficial in environments with multiple GPU servers, as it enables cross-server reallocation.

The AI Computing Broker is a software solution that can be integrated into AI frameworks, allowing for a 50% reduction in GPU usage. It is compatible with both public cloud environments and on-premises setups, and it is already being used by companies in sectors such as finance, data center operations, and AI image analysis services.

A key feature of the FUJITSU-MONAKA is its ability to operate stably at ultra-low voltage. Generally, reducing a CPU's power supply voltage can slow down circuit speeds and complicate stable operation; however, Fujitsu's innovative circuit design effectively addresses these challenges. By lowering the CPU's power supply voltage, power consumption is significantly reduced. These unique technologies allow the FUJITSU-MONAKA to achieve double the application performance (*3) and double the power efficiency (*3) compared to its competitors.
*1) FUJITSU-MONAKA: This is based on results obtained from a project subsidized by the New Energy and Industrial Technology Development Organization (NEDO).
*2) The K computer and the supercomputer Fugaku: jointly developed by RIKEN and Fujitsu.
*3) Based on our performance estimates for the 2027 release. Performance will vary depending on usage conditions, configuration, and other factors.

Explanation from Nina Arataki and Hideki Maeda, Senior Directors of the Mission Critical System Business Unit at Fujitsu Limited.

The rapid growth of AI and the resulting surge in computing demand, especially the surge in GPU computation for AI processing, have led to increased power demands in data centers and increased heat generation from servers. To prevent GPU failure, it is essential to maintain low temperatures, which necessitates additional power for cooling. The latest generation of GPUs released in 2025 requires liquid cooling. In this context, "liquid cooling," which offers higher cooling efficiency than traditional air cooling, is gaining attention as a technology to address increased heat generation in data centers and reduce cooling power consumption.

Liquid cooling uses liquid, which has more than 20 times the thermal conductivity of air, to effectively cool servers and racks. Main methods of liquid cooling include "Direct Liquid Cooling (DLC)," where a liquid cooling device (with circulating coolant) directly contacts the processor inside the server to dissipate heat, and "Rear Door Heat Exchanger (RDHX)," where a liquid cooling device is installed on the rear side of a rack with integrated servers to cool exhaust heat.

Direct liquid cooling can be implemented through two methods: "open-loop liquid cooling," which transports heated coolant outside the server, and "closed-loop liquid cooling," which moves heated liquid to a radiator within the server to release heat into the room air. Fujitsu possesses both technologies, but particularly in closed-loop liquid cooling, it has developed a world-first technology called "boiling cooling (two-phase cooling)," which cools by boiling the coolant and utilizing latent heat of vaporization. This technology was mass-produced and introduced for mission-critical applications in 2017, doubling the cooling performance compared to traditional closed-loop liquid cooling that uses only liquid (single-phase). It also reduces environmental impact compared to two-phase cooling with insulating refrigerants while ensuring human safety.

Open-loop liquid cooling transports high-temperature liquid from servers to cooling towers or chillers via a Coolant Distribution Unit (CDU). This method allows for high-density server configurations in racks by moving server heat outside the building using liquid, and many general-purpose GPU servers adopt this approach. Fujitsu incorporates its design philosophy of non-stop server systems, achieving hot swap redundancy for all units.

While IT infrastructure for liquid cooling exists, many companies hesitate to implement it due to concerns about potential liquid leaks damaging equipment, impacts on electrical systems below, optimal investment decisions for liquid cooling systems, and challenges related to maintenance and operational expertise.

To address these concerns, Fujitsu leverages its liquid cooling technology and expertise to support the design and implementation of optimal cooling facilities (including cooling towers, chillers, and piping) tailored to customers' future server expansion plans as a professional service. Additionally, it offers an all-in-one subscription service that integrates and automatically controls liquid cooling hardware and multiple CDUs, alleviating initial investment and operational challenges. The "Fujitsu Liquid Cooling Management for Datacenter" service is scheduled for release in the first quarter of fiscal year 2025. This liquid cooling software monitors hardware and servers in real-time, controlling multiple CDUs to achieve high reliability, availability, and efficiency for the entire cooling system. These services are available not only to data center operators and companies with their own data centers but also to construction firms building data centers.